US 12,191,840 B2 · Acoustic wave device

Abstract

An acoustic wave device includes a piezoelectric layer and first and second electrodes. The first and second electrodes face each other in a direction crossing a thickness direction of the piezoelectric layer. The acoustic wave device utilizes a bulk wave of a thickness-shear primary mode. The material of the piezoelectric layer is lithium niobate or lithium tantalate. The first and second electrodes include aluminum layers, respectively, on the piezoelectric layer. An orientation direction of a crystal of each of the aluminum layers is a direction orthogonal or substantially orthogonal to a second principal surface on the piezoelectric layer side of each of the aluminum layers.

Claims20

Dependent claims

An acoustic wave device comprising:

a piezoelectric layer;
and
a first electrode and a second electrode facing each other in a direction crossing a thickness direction of the piezoelectric layer;
wherein
a material of the piezoelectric layer is lithium niobate or lithium tantalate;
each of the first electrode and the second electrode includes an aluminum layer on the piezoelectric layer;
and
an orientation direction of a crystal of the aluminum layer is a direction orthogonal or substantially orthogonal to a surface on a piezoelectric layer side of the aluminum layer.

5 more elements

An acoustic wave device comprising:

a piezoelectric layer;
and
a first electrode and a second electrode facing each other in a direction crossing a thickness direction of the piezoelectric layer;
wherein
the first electrode and the second electrode are electrodes adjacent to each other;
when a distance between a center line of the first electrode and a center line of the second electrode is denoted as p, and a thickness of the piezoelectric layer is denoted as d, d/p is not greater than about 0.5 in any cross section along the thickness direction in the acoustic wave device;
a material of the piezoelectric layer is lithium niobate or lithium tantalate;
each of the first electrode and the second electrode includes an aluminum layer on the piezoelectric layer;
and
an orientation direction of a crystal of the aluminum layer is a direction orthogonal or substantially orthogonal to a surface on the piezoelectric layer side of the aluminum layer.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/701,978Filed 23 Mar 2022 · continuation

Priority

JP 2019-17810127 Sep 2019

Published

US 2022/0216848 A17 Jul 2022

Granted

7 Jan 2025

Term ends

Not estimatedThe source records don’t support an estimate.

Classification13 codes

H03H 9/02157
Of bulk acoustic wave devices: dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness
H03H 9/13
Driving means, e.g. electrodes, coils: for networks consisting of piezoelectric or electrostrictive materials
H03H 9/02015
Of bulk acoustic wave devices: characteristics of piezoelectric layers, e.g. cutting angles
H03H 9/02031
Characteristics of piezoelectric layers, e.g. cutting angles: consisting of ceramic

Acoustic wave device

Life of this patent

Acoustic wave device

Life of this patent

Abstract

Claims20